Information related to tissue elasticity or other properties can be useful to a surgeon or other practitioner during a medical procedure. For example, the elasticity modulus of bodily tissue may indicate the presence of a certain type of tissue. In another example, a measurement of tissue elasticity or stiffness may provide information indicative of tissue damage, disease, or other conditions at a targeted tissue site.
A number of instruments can be used to measure the tissue elasticity of a selected portion of bodily tissue. Many on these instruments measure the resulting force or pressure in response to a predetermined indentation or displacement. Conversely, another group of instruments measure the resulting displacement in response to a predetermined force or pressure. For example, some in vitro measurement devices can receive a tissue sample removed from the body and thereafter apply a predetermined indentation or displacement to the tissue sample. The corresponding force required for making the indentation can be detected, and the elastic modulus or other tissue elasticity properties can then be calculated from force-displacement data.
Some tissue elasticity devices are capable of measuring tissue elasticity in vivo, and thus do not require removal of a tissue sample from a body. For instance, some tissue elasticity measurement devices may include an actuator along an end effector to act upon a targeted tissue site in the body. The actuator may be electrically triggered (e.g., piezoelectric actuator or the like) to apply a controlled dynamic load or otherwise act upon the targeted tissue site, and the response from the targeted tissue can then be detected. In such circumstances, the actuator and other structures on the end effector may require a footprint size that thereby limits the types of surgical procedures suitable for the device.